Control mechanism for operating a vehicle

ABSTRACT

In order to more easily control movement of a vehicle such as a tractor, an operator&#39;s left hand can twist a directional actuating member or a juxtaposed speed actuating member about an outstanding axis. These actuating members are rotatably mounted on a tiller arm extending radially from a housing assembly so that the operator can simultaneously use the actuating members and steer the vehicle by pushing or pulling the tiller arm and rotating the housing assembly in the desired direction about an upstanding axis. Push-pull controls are associated with each actuating member and protected within the housing assembly. A bearing assembly guidably supports and permits relative angular movement of each of the push-pull controls to prevent twisting thereof when the housing assembly is rotated.

DESCRIPTION TECHNICAL FIELD

This invention relates to a mechanism for controlling the movement of avehicle, and more particularly to a more effective and operationallyless fatiguing mechanism for simultaneously steering the vehicle andcontrolling the direction of longitudinal movement and speed range ofthe vehicle.

BACKGROUND ART

The control mechanism disclosed in U.S. Pat. No. 4,541,497 to C. W.Riediger, et al on Sept. 17, 1985, and which was specificallyconstructed for steering and operating the transmission of a track-typevehicle, has been extremely well received by the industry. In suchmechanism, a tiller arm extends outwardly from an upstanding memberwhich is rotatable about a fixed axis, and the vehicle is steered as thetiller arm is swung in either direction away from a generally centeredneutral position. In order to change at least one of the speed range ofthe vehicle and the direction of longitudinal movement of the vehicle, ahandgrip portion is supported on the tiller arm for rotation about itsown axis. Thus, the handgrip portion can be conveniently grasped by anoperator's downwardly facing left-hand palm and as the vehicle istraveling forwardly it can be steered to the left by swinging the tillerarm forwardly. Simultaneously, the vehicle can be shifted from a forwardto a reverse speed by merely twisting the handgrip portion about its ownaxis through a relatively limited angular range.

A mechanically separated speed selector lever has heretofore been usedwith the aforementioned steerable tiller arm and its twistable handgripportion. This requires the operator to release the tiller arm and graspthe juxtaposed speed selector lever in order to make a speed range shiftof the vehicle transmission. Upon completing the range shift, the speedselector lever is released and the left hand returned to the tiller arm.This is not only fatiguing and vexatious, but can delay the operator'sattention from other tasks. Normally, the operator's right hand is usedextensively for manipulating an implement control lever, and as theoperator's left hand passes between the separated control members, thereis a slight delay in using the right hand.

In addition, the separated speed selector lever has heretofore beenautomatically forced back to a neutral position when a separate parkingbrake handle has been applied. Consequently, when the parking brake isreleased it is positively assured that the vehicle is in neutral and notin an operating gear. Although the parking brake handle was inconvenientto reach and a relatively complex mechanical connection was used betweenthese control members, it is a desirable feature.

While the control mechanism of aforementioned U.S. Pat. No. 4,541,497 isrugged and reliable, it is relatively complex and costly in constructionbecause of the physically separated operating members and themultiplicity of links and levers associated between each one and theassociated selector spools operated thereby.

Thus, what is desired is a simplified and reliable control mechanism foroperating a vehicle that includes a swingable tiller arm for steeringpurposes, as well as integrated actuating members for separatelycontrolling the direction of longitudinal movement of the vehicle andthe speed range of the vehicle. The tiller arm and associated actuatingmembers should be so constructed and arranged as to fully take intoaccount the principles of economy of motion of a single hand.Preferably, the improved control mechanism should also include a fullyintegrated brake actuating member for engaging a parking brake andsimultaneously assuring neutralization of the transmission associatedwith movement of the vehicle.

The present invention is directed to one or more of the problems as setforth above.

DISCLOSURE OF THE INVENTION

In one aspect of the invention a control mechanism for operating avehicle includes an element mounted for swinging movement about anupstanding first axis, and a tiller arm extending outwardly from theelement along a second axis for controlling steering of the vehicle byswinging the element. Advantageously, first and second actuator deviceshaving first and second actuating members respectively arranged on thetiller arm are used for controlling the direction of longitudinalmovement of the vehicle and the travel speed range of the vehicle.

In another aspect of the invention, a control mechanism is provided foroperating a vehicle including a housing assembly, support means formounting the housing assembly so that it can swing about an upstandingfirst axis, a tiller arm extending from the housing assembly along asecond axis, a first actuating member connected to the tiller arm thatcontrols the direction of longitudinal movement of the vehicle, and asecond actuating member connected to the tiller arm that controls thetravel speed range of the vehicle.

In a further aspect of the invention a control mechanism for operating avehicle includes a housing assembly, first support means for mountingthe housing assembly for swinging movement about an upstanding axis, anactuating member, second support means for mounting the actuating memberon the housing assembly for limited rotation about a second axis,control means for mechanically changing one of the direction and thespeed range of the vehicle, coupling means for connecting the controlmeans to the actuating member, and bearing assembly means for guidablysupporting and permitting relative angular movement of the couplingmeans about a third axis radially offset from the upstanding first axiswhen the housing assembly is swung.

More particularly, a tiller arm extends outwardly of a housing assemblythat is rotatable about an upstanding axis, and the vehicle is steeredas the tiller arm is swung in either direction from neutral. Adirectional actuating member and a speed actuating member are mountedadjacent one another on the tiller arm for limited rotation about asecond axis, such that the operator's downwardly facing hand palm canconveniently grasp either of the actuating members to change thedirection or speed range of the vehicle while simultaneously steeringthe vehicle. A parking brake actuating lever is also secured to theupper portion of the swingable housing assembly, and when it is moved toa BRAKE-ON mode a neutralizing member operates to automatically urge thedirectional actuating member from either of the FORWARD or REVERSEpositions to a centrally located NEUTRAL position. This feature preventsmovement of the vehicle with the vehicle parking brake engaged, and whenthe parking brake actuating lever is subsequently moved to the BRAKE-OFFmode, the transmission remains in NEUTRAL rather than in any positivegear drive mode. Furthermore, the control mechanism employs simple andeffective push-pull control members within the housing assembly for theindividual operation of four hydraulic control valves.

Other aspects and advantages of the present invention will becomereadily apparent upon reference to the accompanying drawings and thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a diagrammatic, rear elevational view of the control mechanism ofthe present invention with portions of the housing walls broken away andcertain elements illustrated in cross section to better show details ofconstruction thereof;

FIG. 2 is a fragmentary, diagrammatic, top plan view of the controlmechanism illustrated in FIG. 1 including portions of a vehicle'soperating station and various control members in the vicinity of theoperator seat;

FIG. 3 is a fragmentary, diagrammatic, cross sectional view as takenalong line III--III of FIG. 1;

FIG. 4 is an enlarged, fragmentary, diagrammatic, cross sectional viewas taken along line IV--IV of FIG. 1;

FIG. 5 is a fragmentary, diagrammatic, cross sectional view of thehousing supporting structure shown in FIG. 1, only as taken from theleft side thereof;

FIG. 6 is a diagrammatic view of the neutralizing member shown in FIG. 4in an elevated BRAKE-OFF condition in solid lines and in a loweredBRAKE-ON condition in phantom lines;

FIG. 7 is an enlarged, fragmentary, diagrammatic cross sectional view ofthe electrical switch assembly of FIG. 1;

FIG. 8 is a diagrammatic view of the electrical switch portion as takenalong line VIII--VIII of FIG. 7;

FIG. 9 is a block diagram plan view of the power train of the vehiclewith four hydraulic control valves associated therewith which areoperated by the control mechanism of FIG. 1;

FIG. 10 is an enlarged, fragmentary sectionalized view through analternate embodiment of the tiller arm, directional actuating member andspeed actuating member shown in FIG. 1; and

FIG. 11 is a fragmentary, external view of the alternate embodimentshown in FIG. 10 illustrating the indicia used therewith.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring to FIG. 2, a transmission, steering, and parking brake controlmechanism 10 constructed in accordance with the present invention isillustrated in conjunction with an operator station 12 of a track-typevehicle identified generally by the reference number 14. The operatorstation includes a tractor seat 16 having left and right arm rests 18and 20, an implement control lever 22, and an auxiliary control lever24. The control lever 22, for example, is of the joy-stick type foradjusting the elevation and tilt angle of a bulldozer blade mounted onthe vehicle. The auxiliary control lever 24 is typically used foroperating a ripper or a winch mounted on the tractor. The location andoperation of such implements are well known in the art although they arenot shown in the drawings. The control levers 22 and 24 are manipulatedby the operator's right hand, while the control mechanism 10 ismanipulated by the operator's left hand.

As is illustrated in FIG. 9, the vehicle 14 also includes an engine orpower plant 11 drivingly connected to a power shift transmission 13having a plurality of forward speeds and a plurality of reverse speeds.The longitudinally oriented transmission powers a cross drive mechanism15 oriented transversely of the vehicle, which has left and right outputmembers 17 and 19. The output members powerably rotate left and rightdrive wheels or sprockets 21 and 23, and left and right parking brakes25 and 27 are operatively connected therewith to inhibit the rotation ofthe individual drive wheels.

As is shown in FIG. 1, the control mechanism 10 includes: (a) a steeringselector apparatus 26 for steering the vehicle 14 by rotating anelevationally lower output lever arm 28 about a fixed upstanding axis30; (b) a first actuator device 32 for controlling the direction oflongitudinal movement of the vehicle by the generally verticaldisplacement of a first push-pull control or cable assembly 34; (c) asecond actuator device 36 for controlling the speed range of the vehicleby the generally vertical displacement of a second push-pull control orcable assembly 38; and (d) a brake and transmission neutralizer device40 for simultaneously restricting movement of the vehicle by thegenerally vertical displacement of a third push-pull control or rodassembly 42 and for urging the first actuator device 32 to a neutralposition by the swinging movement of a neutralizing member 44.

The steering selector apparatus 26 includes a steering selector spool 29which is adapted to be proportionately axially displaced in a firsthydraulic control valve 31 to the counterclockwise turn or clockwiseturn positions. As can be generally appreciated by reference to FIG. 9,the first hydraulic control valve 31 controls the flow of hydraulicfluid between and engine driven steering pump 45 and a reversiblesteering motor 47 selectively driving the cross drive mechanism 15. Forexample, the counterclockwise rotation of the vehicle about its owncentral vertical axis results in a left turn when traveling forwardly.

The first actuator device 32 includes a directional selector spool 33which is adapted to be axially displaced in a second hydraulic controlvalve 35 to either a FORWARD position or a REVERSE position at theopposite sides of a centralized NEUTRAL position as is shown in FIGS. 1and 9. And, the second actuator device 36 includes a speed selectorspool 37 which is axially displaced in a third hydraulic control valve39 to obtain a preselected one of a plurality of speed range positionssuch as FIRST GEAR, SECOND GEAR and THIRD GEAR.

The brake and neutralizer device 40 includes a parking brake selectorspool 41 which can be axially displaced in a fourth hydraulic controlvalve 43 between a BRAKE-OFF position and a BRAKE-ON position.

More particularly, the steering selector apparatus 26 includes a tubulartiller arm 46 defining a central outstanding axis 48 which preferablyextends upwardly at a slight angle from a horizontal plane as isidentified by the letter D in FIG. 1. As is shown in FIG. 2, the centralaxis 48 extends generally toward the fixed upstanding axis 30 in aslightly offset manner, and when the vehicle 14 is travelling in astraight longitudinal direction, the axis 48 is preferably at apreselected angle B forwardly of a transverse vertical plane through theaxis 30.

The tubular tiller arm 46 includes a distal end flange 50 and an outercylindrical surface 52 concentrically arranged along the central axis48, and is rigidly secured to a supporting pedestal element 54intermediate the ends thereof. In turn, the pedestal element isreleasably secured to a swingable housing assembly 56 by a plurality ofthreaded fasteners or bolts 58, one of which is illustrated. As is shownin FIGS. 1 and 5, the housing assembly 56 has an upper profiled case 60,an intermediate tubular portion 62, an intermediate adapter portion 64,and a lower tubular portion 66 arranged along the upstanding axis 30 andreleasably secured together by a plurality of elongate threadedfasteners or bolts 68. A stationary frame 70 has an upper deck 72 and alower deck 74, and upper and lower bearing support structure 76 and 78are provided for mounting the housing assembly 56 for swinging movementabout the upright axis 30. The upper bearing support structure 76includes a ball bearing assembly 80 entrapped between the upper profiledcase 60 and the intermediate tubular member 62, and is generally heldstationary by an annular retaining member or collar 82 releasablyconnected to the upper deck 72 as by a plurality of threaded fastenersor bolts 84. The lower bearing support structure 78 is optional,although it is preferred, and in the instant example includes anotherball bearing assembly 86 contained within a retaining ring device 88.The retaining ring device 88 is releasably secured to the lower deck 74as by the threaded fasteners or bolt and nut assemblies 90, and is usedto stabilizingly center the lower tubular portion 66 of the housingassembly.

The lower part of the intermediate tubular member 62 defines a centralbore 92 on the upstanding axis 30, and a pair of somewhat largerdiameter stepped bores 94 and 96 arranged along a diagonally oppositepair of upstanding and offset axes 98 and 100 respectively and which areradially offset the same distance from the central axis 30. The adapterportion 64 has a corresponding central bore 102, and a pair of bores 104and 106 also arranged along the respective axes 98 and 100.

Turning now to the first actuator device 32, it may be noted to includea tubular directional actuating member or first handgrip portion 108rotatably supported directly by the tiller arm 46. Preferably, the outercylindrical surface 52 of the tiller arm is hardened and/or coated witha material having a relatively low coefficient of friction to moreeffectively support the directional actuating member 108. An outer sealring 109 is located between the directional actuating member 108 and thetiller arm 46 adjacent the distal end flange 50. As best shown in FIG.7, the directional actuating member has a stepped inner flange 110 andan inner seal ring 112 is seated thereon and engaged with the outer faceof the pedestal element 54 of the tiller arm 46. An arcuately-shapedelectrical switch assembly 114 is located between the pedestal element54 and the flange 110 of the directional actuating member and two blindrectangular pockets 116 are defined in the inner flange 110, althoughonly one of which is illustrated. Each of the pockets is adapted toreceive a piston 118 therein which is biased to the left when viewingthe drawing by a compression spring 120.

Furthermore, the first actuator device 32 has an inwardly extendingcylindrical projection 122 which is illustrated in FIGS. 1 and 3. Thisprojection is rigidly secured to the inner flange 110 of the directionalactuating member 108 at a preselected radius from the central axis 48 ofthe tiller arm 46 and parallel to that axis. A cylindrical ring 123 isfixedly secured to the projection 122, although it can be adapted tofreely rotate thereon if desired. The projection extends through anarcuate or kidney-shaped slot 124 defined fully through the pedestalelement 54, and at the inner end thereof has a ball assembly 126releasably secured thereto. The first push-pull cable assembly 34 has atits upper extremity an extendable socket head 128 which receives theball assembly. Such ball and socket coupling arrangements are quicklyconnected and disconnected and are widely available. The socket head isconnected to a depending cable 130 which is contained within a tubularsheath 132 and an outer protecting wrap 134. The distal end of thiscable is connected to the directional selector spool 33.

Advantageously, a first ball bearing assembly 136 is provided forguidably supporting and permitting relative angular movement of thepush-pull cable assembly 34 within the housing assembly 56 and about itsown offset axis 100 as the housing assembly is limitedly swung about thecentral upstanding axis 30. The ball bearing assembly is exteriorlyseated in the stepped bore 96 of the tubular member 62, and internallyseated on the outer protecting wrap 134 such that it guidably centersthe protecting wrap and sheath 132. At least a portion of the protectingwrap is threaded so that an upper nut 138 and a lower nut 140 can bescrewthreadably adjusted thereon in an entrapping relationship with theinner race of the ball bearing assembly. The outer race thereof iscontained by the adapter portion 64 of the housing assembly.

The second actuator device 3 includes a knob-like speed actuating memberor second handgrip portion 142 releasably secured to the distal end ofan elongate cylindrical shaft 144. A pair of needle bearings or sleevebearings 146, the outer one of which is shown, rotatably support theopposite ends of the shaft within the tubular tiller arm 46. Theproximal end of the shaft has a radius arm 147 with a ball assembly 148releasably secured thereto. This ball assembly is contained within anextendable socket head 150 connected to the upper end of the secondpush-pull cable assembly 38. A depending cable 152 is connected to thesocket head and is adapted to slide within a tubular sheath 154 and anouter, externally threaded protecting wrap 156 in a manner similar tothat described with respect to the push-pull cable assembly 34. A secondball bearing assembly 158 is provided for guidably supporting andpermitting relative angular movement of the push-pull cable assembly 38within the housing assembly 56 about its own offset axis 98 as thehousing assembly is limitedly rotated. But since the first and secondball bearing assemblies 136 and 158 are preferably identical, the latterneed not be further described.

Attention is now directed to FIGS. 1 and 4 and to the brake andtransmission neutralizer device 40 which includes a parking brakeactuating member or lever 160 movable between a rearwardly disposedBRAKE-OFF position shown in solid lines and a forwardly disposedBRAKE-ON position shown in phantom lines. The generally U-shaped leverhas a spherical knob 162 at the upper end thereof, and a cylindricalmounting portion 164 at the lower end which is mounted for limitedrotation about an axis 166 by a support structure 167 including a pairof needle bearings or sleeve bearings 168 seated within the upperprofiled case 60. A tubular sleeve 170 is connected to rotate with themounting portion 164 by a spline joint 172, and has the neutralizingmember 44 integrally secured thereto at one end. At the opposite end apair of lever arms or mounting ears 176 extend integrally therefrom.These ears are connected to an upper spring seat 178 by a pivot pin 180.A lower spring seat 182 is connected to the inner portion of theprofiled case 60 by a ball and socket joint identified generally by thereference number 184, and a coiled compression spring 186 extendsbetween the two seats. The pivot pin 180 is located at the upper side ofa plane 188 passing through the ball and socket joint and the axis 166when the lever 160 is in the BRAKE-OFF position, and is located at thelower side of the plane when the lever is in the BRAKE-ON position.

A lever arm 190 is secured to the mounting portion 164 of the parkingbrake actuating lever 160 intermediate the opposite ends thereof. Anupper portion 192 of the brake push-pull rod assembly 42 is connected tothis lever arm through a pivot joint 194. A lower portion 196 dependsthrough the adapter bore 102 and generally along the axis 30 and sincethe upper portion is slightly inclined with respect to the lowerportion, another ball and socket joint 198 is used to connect them. Oneor more elastomeric or plastic guide rings 200 can be used, if desired,to guide the lower portion 196 within the adapter bore or within thelower tubular portion 66 for concentricity with the axis 30. The distalend of the lower portion 196 is connected to the parking brake selectorspool 41, which can be arranged concentrically along central axis 30, ifdesired.

Referring to FIGS. 4 and 6, the neutralizing member 44 of the brake andneutralizer device 40 includes a generally C-shaped cam plate 174 whichis profiled to define an arcuate slot 202 and a pair of contoured entryramps 204 and 206 at the opposite sides of the slot which cooperate withthe cylindrical ring 123 on the projection 122 of the directionalactuating member 108 as will later be explained.

Turning next to the construction of the electrical switch assembly 114shown in FIGS. 7 and 8, it includes an arcuately shaped circuit board208 releasably secured to the pedestal element 54 by a plurality ofscrews 210. The circuit board is preferably of a nonconducting plasticmaterial and has first, second, third and fourth electrically conductingportions 212,214,216 and 218 on the outer surface thereof. A wiringharness or electrical cable assembly 219 has four electricallyconducting wires, not shown, that are individually connected to the fourelectrically conducting portions. A first or upper wiper bridge 220rotates about the axis 48 since it is contained within the swingableactuating member 108. The electrically conductive upper wire bridge 220is biased by the piston 118 and the compression spring 120 toward thecircuit board, and has two inwardly projecting buttons 222 and 224. Theupper wiper bridge 220 thus cooperates with the upper pair of conductingportions 212 and 214. A second or lower wiper bridge 226 is similar tothe upper wiper bridge 220 and has a pair of inwardly projecting buttons228 and 230 that cooperate with the lower pair of conducting portions216 and 218.

Alternate Embodiment

Referring to FIGS. 10 and 11, an alternate embodiment tiller arm 46' isillustrated with a directional actuating member 108' and a speedactuating member 142' supportably mounted thereon by a needle or sleevebearing 146' and a needle or sleeve bearing 232 respectively. Theactuating members have generally elongate external conical surfaces 234and 236 suitably knurled or provided with elongate grooves 238 to aid ingripping them. The flange 50' of the tiller arm has an externalcylindrical surface 240 that is marked with a reference mark 242. Thedirectional actuating member has directional indicia R,N and F on thesurface 234 that are selectively positionable with respect to the"stationary" reference mark 242, and the speed actuating member hasspeed range indicia 1,2 and 3 on the surface 236 that are selectivelypositionable with respect to the reference mark.

Industrial Applicability

The operator's left hand palm can face downwardly and rest comfortablyabout the directional actuating member 108 shown in FIG. 1. It is aneasy motion to rotate it in a clockwise direction when looking inwardlyalong the axis 48 to the FORWARD mode from the NEUTRAL position of theprojection 122 shown in FIG. 3, or in a counterclockwise direction tothe REVERSE mode from the NEUTRAL position. The angular movementidentified by the letter C is approximately 35° in each instance. Whenthe projection is in the FORWARD mode, the ball and socket joint 126,128shown in FIG. 1 is elevated and this raises the elongate cable 130connected to the directional selector spool 33 and pulls it outwardly ofthe second hydraulic control valve device 35. When the projection islowered for the REVERSE mode, the cable 130 is pushed to retract thedirectional selector spool. It should be appreciated that the lower endof the cable extends through a curved path to the directional selectorspool which could be at almost any angular orientation.

The speed actuating member 142 is typically located in FIRST GEAR andmay be rotated therefrom in even increments in a clockwise directionwhen viewing inwardly along the axis 48 of FIG. 1 to the SECOND GEAR andTHIRD GEAR positions. With such rotation of the speed actuating member,the radius arm 147 illustrated in FIG. 4 is moved in a counterclockwiseposition. This elevates the cable 152 and pulls the speed selector spool37 outwardly of the third hydraulic control device 39. The cable 152also is curved at its lower end and is somewhat parallel to the cable130, although FIG. 1 is diagrammatically inaccurate in this respect,since the control valves 35 and 39 are preferably juxtaposed as isindicated in FIG. 9.

During straight longitudinal movement of the track-type vehicle 14, thetubular tiller arm 46, and the housing assembly 56 are positioned in theNEUTRAL position identified by the letter "N" in FIG. 2. The NEUTRALposition is located at an angle B of about 15° forward of a transversevertical plane through the upstanding axis 30. If it is desired to steerthe vehicle to the left when travelling forwardly, the tiller arm isurged forwardly or in a counterclockwise direction about upstanding axis30. Advantageously, the vehicle rotates or changes its steering headingin the same direction that the tiller arm is swung about the axis 30.This causes the corresponding angular movement of the housing assembly56 on the ball bearing assembly 80 and the output lever arm 28 shownnear the bottom of FIG. 1. The counterclockwise movement of the outputlever arm 28 pulls the steering selector spool 29 outwardly of the firsthydraulic control device 31 through any intermediate and conventionalcoupling means 49 as indicated by the broken lines. The steering motor47 is then caused to operate in the desired direction and at the desiredrate of speed such that the right output member 19 of the cross drivemechanism 15 of FIG. 9 is accelerated and the left output member 17 isdecelerated by approximately the same amount. The vehicle issubsequently caused to rotate in a counterclockwise direction about itsown central vertical axis and to turn to the left. Of course, theclockwise movement of the tiller arm will correspondingly urge thesteering selector spool 29 inwardly to cause clockwise rotation of thevehicle and a right turn when traveling forwardly. When the direction oflongitudinal travel is changed to reverse, the forward displacement ofthe tiller arm 46 will still cause counterclockwise rotation of thevehicle about its own central vertical axis. Both the fullcounterclockwise and full clockwise vehicle turning positions,identified respectively by the letters "CCW" and "CW" are located at anangle A of about 25° from the neutral position. As is shown in FIG. 1,the steering arm axis 48 is inclined upwardly at an angle D of about 15°for comfort, since the forearm and wrist are more relaxed thereat thanwould be the case with a horizontal steering arm axis.

One of the features of the control mechanism 10 is that both of thepush-pull cable assemblies 34 and 38 are guidably centered by the ballbearing assemblies 136 and 158 at a fixed radius away from the centralupstanding axis 30. Thus, when the housing assembly 56 is rotated ineither direction away from NEUTRAL during steering, the cable assemblies136 and 58 are individually allowed to rotate about their own axes 100and 98. Permitting them to freely rotate relative to the housingassembly automatically relieves any twisting strains thereon since thelower ends of the cable assemblies 34 and 38 are positively connected tothe frame-supported directional and speed selector spools 33 and 37respectively. If these cable assemblies were not allowed to freelyrotate, there would be a tendency for them to twist and cause anundesirable increase in resilient torque acting against the swingingmovement of the steering selector apparatus 26 about its upstanding axis30.

Referring now to the brake and neutralizer device 40 shown in FIGS. 1and 4, the parking brake actuating lever 160 may be urged forwardly bythe operator's left hand from the solid line BRAKE-OFF position to thephantom line BRAKE-ON position. In so doing, the mounting portion 164,the sleeve 170 and the lever arm 190 are rotated in a counterclockwisedirection about the axis 166 when viewing FIG. 4. In doing this, thepivot pin 180 is moved in an arc about the axis 166 from a location atthe upper side of the plane 188 to the lower side of that plane. Thecompression spring 186 is gradually compressed until the pivot pinpasses through the plane, and thereafter the compression spring expandsand positively urges the lever toward the BRAKE-ON position with adesirable over-center action. The pivot joint 194 and third push-pullrod assembly 42 are subsequently urged downwardly and the parking brakeselector spool 41 is pushed into the fourth hydraulic control valvedevice 43 to simultaneously engage the left and right parking brakes 25and 27 of the vehicle, shown in FIG. 9.

When the parking brake actuating lever 160 is moved to the forwardBRAKE-ON position, the profiled cam plate 174 is also caused to move ina counterclockwise direction when viewing FIGS. 4 and 6. In the eventthat the operator had positioned the directional actuating member 108 inFORWARD wherein the cylindrical projection 122 and ring 123 arearcuately disposed in an elevated position, the cam plate 174 wouldcontact the ring and urge it downwardly. Specifically, as is shown inFIG. 6, the inner entry ramp 204 would contact the elevated ring asindicated in phantom lines by the reference number 123' and forciblydepress it to the solid line position illustrated. In a similar manner,if the operator had earlier positioned the directional actuating member108 in REVERSE, the ring 123 would be in a lowered position as indicatedin phantom lines by the reference number 123' . The subsequentcounterclockwise movement of the neutralizing member 44 and cam plate174 would cause the outer entry ramp 206 to abut the ring and to urge itupwardly toward its neutral position shown in solid lines. The arcuateslot allows the cam plate to avoid contact with the tubular tiller arm46 until the desired amount of travel is provided for the thirdpush-pull rod assembly 42.

The electrical switch assembly 114 illustrated in FIGS. 7 and 8 preventsinadvertent starting of the vehicle 14 with the transmission 15 in anactive gear mode by requiring that the directional actuating member 108be positively positioned in NEUTRAL. In this position the projection 122is located centrally of the slot 124 as is illustrated in FIGS. 1 and 3.In such angular location, the lower wiper bridge 226 electricallybridges the third and fourth electrically conducting portions 216 and218. Electrical energy is thus allowed to be conducted by the wiringharness 219 to an external electrical control circuit, not shown, forstarting the engine 11. If the directional actuating member 108 is inthe FORWARD mode, the wiper bridge 226 is located at the 6 o'clockposition when viewing FIG. 8, and if the directional actuating member isin the REVERSE mode, the wiper bridge 226 is located approximately atthe 4 o'clock position. In either of these locations the wiper bridge isdisplaced away from the fourth electrically conducting portion 218, andthis effectively prevents electricity from passing through the lowerwiper bridge and prevents inadvertently starting of the vehicle with thetransmission in either FORWARD or REVERSE.

Assuming that the engine is started and running, the directionalactuating member 108 can be rotated from NEUTRAL to REVERSE. As can beappreciated by reference to FIG. 8, the upper wiper bridge 220 issimultaneously moved about the axis 48 from the position illustratedwherein no electricity is conducted therethrough. After a relativelylimited angular degree of movement, the button 222 makes electricalcontact with the first electrically conducting portion 212. Accordingly,electrical energy is communicated across the upper wiper bridge andthrough the wiring harness 219 to actuate a warning horn, not shown.This signal alerts those around the vehicle that it is or is about thebe backing up.

In view of the foregoing, it can be appreciated that the operator's lefthand efficiently controls the mechanical displacement of four differentselector spools 29,33,37 and 41 by the manipulation of the controlmechanism 10 through relatively simple and economical push-pull controls34,38 and 42 and a rotating housing assembly 56. The operator's lefthand can be easily positioned over the directional actuating member 108or 108' and the wrist limitedly rotated in a clockwise direction whenlooking inwardly along the axis 48 to obtain one of the REVERSE, NEUTRALor FORWARD modes, or over the juxtaposed speed actuating member 142 or142' and the wrist twisted to obtain one of the FIRST, SECOND or THIRDSPEED modes. In either case, the operator's left arm may besimultaneously extended or retracted to rotate the tiller arm 46 and thehousing assembly 56 about the upstanding axis 30 to steer the vehicle inthe desired direction. Moreover, the operator can convenientlyreposition his left hand from either of these actuating members to theparking brake actuating lever 160 to urge it forwardly to the BRAKE-ONmode when he is through the work task. This movement will cause thedirectional actuating member 108 of the first actuator device 32 to beautomatically placed into the NEUTRAL mode in the event that it wasinadvertently left in either FORWARD or REVERSE. This will minimize useof the parking brakes as service brakes and extend the service lifethereof, and should the parking brake actuating lever be immediatelyreturned to the BRAKE-OFF mode will prevent inadvertent movement of thevehicle in a positive drive mode. In this regard it should be noted thatthe vehicle 14 has conventional left and right service brakes, notshown, in operational relationship with the left and right outputmembers 17 and 19 of the cross drive mechanism 15 in a well knownmanner. Since the engine 11 is frequently turned off when the parkingbrakes 25 and 27 are in the BRAKE-ON mode, the restarting of the powerplant can be established only in the NEUTRAL position of the directionalactuating member 108 by the electrical switch assembly 114, and this isalso advantageous.

Other aspects, objects and advantages will become apparent from a studyof the specification, drawings and appended claims.

We claim:
 1. A control mechanism for operating a vehicle having anelement mounted on the vehicle for swinging movement about an upstandingfirst axis, and a tiller arm extending outwardly from the element alonga second axis and controlling steering of the vehicle by swinging theelement about the first axis, comprising:first actuator means forcontrolling the direction of longitudinal movement of the vehicleincluding a directional actuating member; and second actuator means forcontrolling the speed range of the vehicle including a speed actuatingmember, the directional and speed actuating members being arranged onthe tiller arm for independent rotation about the second axis.
 2. Acontrol mechanism for operating a vehicle having an element mounted onthe vehicle for swinging movement about an upstanding first axis, and atiller arm extending outwardly from the element along a second axis andcontrolling steering of the vehicle by swinging the element about thefirst axis, comprising:first actuator means for controlling thedirection of longitudinal movement of the vehicle including adirectional actuating member rotatably connected to the tiller arm; andsecond actuator means for controlling the speed range of the vehicleincluding a speed actuating member rotatably connected to the tillerarm.
 3. The control mechanism of claim 2 wherein the directionalactuating member is tubular and externally mounted on the tiller arm. 4.The control mechanism of claim 3 wherein the second actuating meansincludes a shaft rotatably mounted within the tiller arm and the speedactuating member is connected to the shaft.
 5. The control mechanism ofclaim 2 wherein the element includes a housing assembly, and the firstactuator means includes a first push-pull control and a first bearingassembly for guidably supporting the first push-pull control within thehousing assembly on a third axis radially offset from the first axis. 6.The control mechanism of claim 5 wherein the second actuator meansincludes a second push-pull control and a second bearing assembly forguidably supporting the second push-pull control within the housingassembly on a fourth axis radially offset from the first axis.
 7. Thecontrol mechanism of claim 6 wherein the first actuator means includesfirst coupling means for connecting the directional actuating member tothe first push-pull control, the second actuator means includes secondcoupling means for connecting the speed actuating member to the secondpush-pull control, the directional actuating member and the speedactuating member being substantially juxtaposed concentrically along thesecond axis.
 8. A control mechanism for operating a vehicle comprising:ahousing assembly; support means for mounting the housing assembly on thevehicle for swinging movement about an upstanding first axis; a tillerarm extending outwardly from the housing assembly along a second axis; afirst actuating member connected to the tiller arm and controlling thedirection of longitudinal movement of the vehicle; and a secondactuating member connected to the tiller arm and controlling the speedrange of the vehicle, the first and second actuating members beingsubstantially juxtaposed on the tiller arm for individual rotation aboutthe second axis.
 9. The control mechanism of claim 8 including first andsecond push-pull controls dependingly arranged within the housingassembly, and first and second coupling means for respectivelyconnecting the first and second actuating members to the first andsecond push-pull controls.
 10. The control mechanism of claim 9including bearing assembly means for respectively guidably supportingthe first and second push-pull controls within the housing assemblyalong axes offset from the first axis.
 11. A control mechanism foroperating a vehicle comprising:a housing assembly; support means formounting the housing assembly on the vehicle for swinging movement aboutan upstanding first axis; a tiller arm extending outwardly from thehousing assembly along a second axis; a first actuating member rotatablyconnected to the tiller arm for movement from a central neutral positionto one of a forward position and a reverse position and controlling thedirection of longitudinal movement of the vehicle; a shaft rotatablymounted within the tiller arm; and a second actuating member connectedto the shaft for movement between a plurality of speed positions andcontrolling the speed range of the vehicle.
 12. The control mechanism ofclaim 11 including a directional selector spool, a speed selector spool,and first coupling means for connecting the first actuating member tothe directional selector spool and second coupling means for connectingthe second actuating member to the speed selector spool.
 13. The controlmechanism of claim 12 wherein the first coupling means includes a firstpush-pull cable assembly and the second coupling means includes a secondpush-pull cable assembly dependingly arranged within the housingassembly.
 14. The control mechanism of claim 11 wherein the controlmechanism includes electrical means on the tiller arm for initiating awarning signal in response to rotating the first actuating member to thereverse position.
 15. The control mechanism of claim 11 wherein thecontrol mechanism includes electrical means on the tiller arm forallowing the vehicle to be started solely when the first actuatingmember is rotatably disposed in the neutral position.
 16. A controlmechanism for operating a vehicle comprising:a housing assembly; firstsupport means for mounting the housing assembly on the vehicle forswinging movement about an upstanding first axis; an actuating member;second support means for mounting the actuating member on the housingassembly for limited rotation about a second axis; control meansincluding a push-pull control for mechanically changing one of thedirection and the speed range of the vehicle; coupling means forconnecting the push-pull control to the actuating member; and bearingassembly means for guidably supporting and permitting relative angularlymovement of the push-pull control within the housing assembly about athird axis radially offset from the first axis when the housing assemblyis swung.
 17. The control mechanism of claim 16 wherein the push-pullcontrol is a cable assembly dependingly arranged within the housingassembly for selecting one of forward, neutral, and reverse positions.18. The control mechanism of claim 17 including another actuating membermounted on the housing assembly for limited rotation about the secondaxis by the second support means, and wherein the control means includesanother push-pull cable assembly connected to the another actuatingmember and dependingly arranged within the housing assembly forselecting one of first speed, second speed, and third speed positions.19. The control mechanism of claim 18 wherein the respective push-pullcable assemblies are generally diametrically oppositely disposed, andthe control mechanism includes a further push-pull control arrangedcentrally along the first axis.